The traditional way of allocating a single channel,such as a telephone trunk,among multiple competing users is to chop up its ( ) by using one of the multiplexing schemes, such as FDM. If there are N users, the bandwidth is divided into N equal-sized portions,with each user being assigned one portion.Since each user has private frequency ( ) ,there is now no interference among users.When there is only a small and constant number of users,each of which has a steady stream or heavy load of ( )this division is a simple and efficent allocation mechanism.A wireless example is FM radio stations.Each station gets a portion of the FM band and uses it at most of the time to broadcast its signal. However when the number of senders is large and varying or the traffic is ( ) ,FDM presents some problems.If the spectrum is cut up into N regions and fewer than N users are currently intrested in communicating ,a large piece of valuable spectrum will be wasted.And if more than N users want to communicate ,some of them will be denied ( )for lack of bandwidth,even if some of the users who have been assigned a frequency band ever transmit or receive anything.
问题1选项
A.capability
B.capacity
C.ability
D.power
问题2选项
A.band
B.range
C.domain
D.assignment
问题3选项
A.traffic
B.data
C.information
D.communications
问题4选项
A.Continuous
B.steady
C.bursty
D.flow
问题5选项
A.allowance
B.connection
C.percussion
D.permission
( )is that it provides guidance and direction on how quality will be managed and verified throughout the project.
( )the process of determining,documenting,and managing stakeholder needs and requirements to meet Project objectives.
The information security management system preserves the confidentiality,integrity and availability of information by applying a( ).
( )is a decentralized database,ensure that the data will not be tampered with and forged.
( )puts computer resources on the web,and must meet the requirements of super capacity,super concurrency,super speed and super security.
分配甲、乙、丙、丁四个人去完成五项任务。每人完成各项任务时间如表所示。由于任务多于人数,故规定其中有一个人可兼完成两项任务,其余三人每人完成一项。为了花费时间最少,( )应该完成两项任务。
已知某公司生产AB两种产品,其中生产1件A产品需要1个单位的甲资源,3个单位的丙资源;生产1件B产品需要2个单位的乙资源和2个单位的丙资源。已知现有甲乙丙三种资源4个单位、12个单位和18个单位。通过市场预测,可知A产品的单位市场利润为2元,B产品的单位市场利润为5元。该公司获得最大的市场利润应生产A产品(68)件,此时(69)资源仍有剩余。
已知某公司生产AB两种产品,其中生产1件A产品需要1个单位的甲资源,3个单位的丙资源;生产1件B产品需要2个单位的乙资源和2个单位的丙资源。已知现有甲乙丙三种资源4个单位、12个单位和18个单位。通过市场预测,可知A产品的单位市场利润为2元,B产品的单位市场利润为5元。该公司获得最大的市场利润应生产A产品(68)件,此时(69)资源仍有剩余。
某项目2016年投资额12万元,2018年开始取得项目的净收益(产品一原料辅料及公用工程)6万元/年,2018-2021年每年还会产生其他成本(包括人员工资、管理成本、制造成本等)1.1万元/年;増值税0.35万元/年、营业税金及附加0.05万元/年。则该项目的静态投资回收期为(66)年,截止到2021年底该项目的投资收益率是(67)。
安全审计的手段主要包括( )。